Boosting Solar Hydrogen Production of Molybdenum Tungsten Sulfide-Modified Si Micropyramids by Introducing Phosphate
| Autor: | Chaochin Su, Chih Jung Chen, Da-Hua Wei, Ru-Shi Liu, Chia-Hsien Chen, Karthika Pichaimuthu, Yung-Tao Chen |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
chemistry.chemical_classification
Materials science Sulfide Band gap Tungsten disulfide chemistry.chemical_element 02 engineering and technology Tungsten Overpotential 021001 nanoscience & nanotechnology chemistry.chemical_compound chemistry Chemical engineering Molybdenum General Materials Science Thin film 0210 nano-technology Molybdenum disulfide |
| Zdroj: | ACS applied materialsinterfaces. 12(37) |
| ISSN: | 1944-8252 |
| Popis: | Si is regarded as a promising photocathode material for solar hydrogen evolution reaction (HER) because of its small band gap and highly negative conduction band edge. However, bare Si electrodes have high overpotential because of sluggish HER kinetics on the surface. In this study, molybdenum tungsten sulfide (MoS2-WS2) was decorated on Si photocathodes as the co-catalyst to accelerate HER kinetics. The catalytic performance of MoS2-WS2 was further enhanced by introducing phosphate materials. Phosphate-modified molybdenum tungsten sulfide (PO-MoWS) was deposited on Si photoabsorbers to provide an optimal current of -15.0 mA cm-2 at 0 V. Joint characterizations of X-ray photoelectron and X-ray absorption spectroscopies demonstrated that the phosphate material dominantly coordinated with the WS2 component in PO-MoWS. Moreover, this phosphate material induced a large number of sulfur vacancies in the PO-MoWS/Si electrodes that contributed to the ideal catalytic activity. Herein, TiO2 thin films were prepared as the protective layer to improve the stability of photocathodes. The PO-MoWS/2 nm TiO2/Si electrode maintained 83.8% of the initial photocurrent after chronoamperometric measurement was performed for 8000 s. |
| Databáze: | OpenAIRE |
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